Avian pathogenic Escherichia coli (APEC) infection is responsible for great economic losses to the poultry industry worldwide and there is increasing evidence of its zoonotic importance. In this study, 219 E. coli isolates from 84 poultry flocks in Egypt, including 153 APEC, 30 avian fecal E. coli (AFEC), and 36 environmental E. coli, were subjected to phylogenetic grouping and virulence genotyping. Additionally, 50 of these isolates (30 APEC from colisepticemia and 20 AFEC) were subjected to a more-extensive characterization which included serogrouping, antimicrobial susceptibility analysis, screening for seven intestinal E. coli virulence genes (stx1, stx2, eae, espP, KatP, hlyA, and fliCh7), multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and in vivo virulence testing. More than 90% of the total APEC examined possessed iroN, ompT, hlyF, iss, and iutA, indicating that Egyptian APECs, like their counterparts from the United States, harbor plasmid pathogenicity islands (PAIs). The majority of APEC and AFEC were of phylogenetic groups A, B1, and D. For the 50-isolate subgroup, more than 70% of APEC and 80% of AFEC were multidrug resistant. Among the subgroup of APEC, MLST analysis identified 11 sequence types (ST) while seven STs were found among AFEC. Based on PFGE, the genetic relatedness of APEC and AFEC ranged from 50%–100% and clustered into four primary groups at 50% similarity. Two of the eight APEC strains tested in chickens were able to induce 25% mortality in 1-day-old chicks. APECs were distinguished from AFECs and environmental E. coli by their content of plasmid PAI genes, whereas APEC isolated from colisepticemia and AFEC were not distinguishable based on their antimicrobial resistance patterns, as both groups were multidrug resistant. Avian E. coli strains from broiler flocks in Egypt show similar sequence types to E. coli associated with human infection.
Caracterización molecular y fenotípica de Escherichia coli aislada de parvadas de pollos de engorde en Egipto.
La infección por Escherichia coli patógena para las aves (con las siglas en ingles APEC) es responsable por grandes pérdidas económicas en la industria avícola a nivel mundial y existe una evidencia creciente acerca de su importancia como zoonosis. En este estudio, 219 aislamientos de E. coli de 84 parvadas avícolas en Egipto, incluyendo 153 cepas patógenas aviares de E. coli, 30 cepas E. coli patógenas aviares de heces (AFEC), y 36 cepas de E. coli de ambiente, fueron sujetas a clasificación filogenética y genotipificación por virulencia. Adicionalmente, 50 de estos aislamientos (30 E. coli patógena para las aves y 20 E. coli patógenas aviares de las heces) fueron sujetas a una caracterización más extensiva que incluyó determinación de grupo por serología, análisis de susceptibilidad antimicrobiana, escrutinio para siete genes de virulencia intestinal de E. coli
